Acetazolamide (ACZ) lowers intraocular pressure (IOP), acutely in normal eyes and both acutely and chronically in eyes with glaucoma, and cerebrospinal fluid pressure (CSFp), chronically in patients with idiopathic intracranial hypertension (IIH). We hypothesize chronic daily ACZ would significantly reduce IOP and contribute to a translaminar pressure gradient change reflected by alteration in the CSFp-IOP difference and the deformation of the neural canal in patients with IIH and no glaucoma.
Before randomization to ACZ or placebo treatment for 6 months, 165 participants in the IIH Treatment Trial had evaluations that included Goldmann applanation, CSFp measurement, and optical coherence tomography determination of the neural canal deformation. These measures were repeated at the 6-month outcome.
The IOP was not significantly decreased from baseline at 1, 3, or 6 months in eyes in both treatment groups. At month 6, the amount of ACZ or weight modification did not correlate with any IOP change. The 6-month mean change in neural canal deformation was 0.96 and −0.04 (P=0.001) and in CSFp was −128 and −38 mm H2O (P=0.001), but CSFp-IOP difference change was not significant, in the ACZ and placebo groups, respectively.
ACZ does not reduce the IOP in eyes without glaucoma but does decrease the pathologic elevated CSFp, providing evidence that normal systems can compensate for chronic medication effects. The CSFp-IOP is not a direct marker of translaminar pressure gradient and the ACZ normalization of the neural canal deformation appears due to CSFp reduction alone.
*Department of Neuro-Ophthalmology, New York Eye and Ear Infirmary and Icahn School of Medicine at Mount Sinai, New York, NY
†Department of Electrical and Computer Engineering, The University of Iowa
‡Iowa City VA Health Care System and Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, IA
Supported by U10 EY017281-01A1, U10 EY017387-01A, R01 EY023279.
Disclosure: The authors declare no conflict of interest.
Reprints: Mark J. Kupersmith, MD, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, New York, NY 10029 (e-mail: firstname.lastname@example.org).
Received September 9, 2018
Accepted December 22, 2018